So, based on the recommendations I got from Head-Fi, I wound up going for a pair of Shure SRH440 headphones, which are absolutely fantastic. Now I just need to pick up a sound card that can do Dolby Headphone or CMSS 3D for gaming and I'll be set.

In that respect, I'm eyeballing a Xonar U3 for my laptop, and either a Xonar DG or DX for my desktop.